image: NASA's Aqua satellite passed over huge Tropical Storm Muifa on July 29, 2011 at 04:17 UTC (12:17 a.m. EDT. The infrared image revealed a large area of powerful, high thunderstorms with cold cloud tops (purple) east and west of the center where cloud temperatures were colder than -63 Fahrenheit (-52 Celsius). Muifa is about 1000 miles wide. view more
Credit: NASA JPL, Ed Olsen
The width of an image from the AIRS instrument that flies on NASA's Aqua satellite is about 1700 km (1056 miles), and the clouds and thunderstorms associate with Tropical Storm Muifa take up that entire distance on today's imagery.
Tropical Storm Muifa is spinning through the western North Pacific Ocean today and has grown in size. When NASA's Aqua satellite passed over the storm on July 29, 2011 at 04:17 UTC (12:17 a.m. EDT) it measured the temperatures in the cloud tops. Those cloud top temperatures especially in the east and western sides of the tropical storm were colder than -62 Fahrenheit/-52 Celsius, indicating strong storms with heavy rainfall. Fortunately, much of that heavy rainfall was over open ocean.
Today's image shows that the center of the storm appears almost cloud free and there was strong convection (rapidly rising air that form thunderstorms) and strong thunderstorms on the east, south and western sides of the storm. Convection on the north side of the tropical storm is still being suppressed by the same weather system that affected it yesterday.
At 1500 UTC (10 a.m. EDT) on July 29, Tropical Storm Muifa had maximum sustained winds near 55 knots (63 mph/101 kmh) and was moving north at 6 knots (7 mph). It was located about 815 nautical miles south-southeast of Kadena Air Base near 14.1 North and 133.9 East.
The Joint Typhoon Warning Center forecasters expect Muifa to strengthen over the next couple of days as it moves north across the Pacific.